Ready to be even more confused? La semana proxima and la proxima semana are both valid constructions. You can place proxima/pasada before a noun for example: La pasada reunión del grupo de trabajo fue un éxito (the last meeting of the working group was a success), or after "En la reunión pasada del grupo de trabajo, resolvimos todos nuestros problemas. (We solved all our problems in the last meeting of the working group). I've seen proxima and pasada used more often before a noun than after, but both are correct. However, when used with "semana", "mes", "año" they are more often used after the noun. Isn't it fun ?
There are also some adjectives that change the meaning of the sentence depending on their location. For example: un hombre pobre (a poor man), un pobre hombre (an unfortunate man).
In general though, opposite to english, the adjective will come after the noun. "Una casa bonita" (a beautiful house), "il perro xxxx " (the black dog), "un plato picante" (a spicy dish).
A bit more info there: https://www.spanishdict.com/guide/adj...